[0001] The present invention relates to a device and method for preventing unauthorized
starting of a vehicle.
[0002] In the prior art devices are known that prevent vehicles from starting, to exclude
the possibility of unauthorized use, for example to prevent theft. Such devices are
usually based on an identification/authentication procedure in which, when the key
is inserted into the vehicle's ignition switch, to start the engine, data are exchanged
between the ignition key and a control module incorporated in the vehicle. If the
module validates and enables the key, the engine can be started, otherwise it cannot.
[0003] The key incorporates an electromagnetic device, known as a "transponder", that is
activated when in proximity to the control module, with which it exchanges a secret
identification code (electronic key).
[0004] Once the key has been enabled/validated the control module allows the fuel to be
delivered to the engine so that it can start.
[0005] These known enabling procedures are still not able to guarantee an adequate level
of security, since it may be possible to find other ways of starting the vehicle even
without using the proper ignition key.
[0006] The purpose of this invention is to overcome all the drawbacks (solve the problems)
described above and providing a device and method for preventing unauthorized starting
of a vehicle so that it is possible to extend the level of control and immobilize
the vehicle more effectively, by controlling all the electronic circuits that manage
vehicle kinematics functions, not only when the vehicle is parked and/or the engine
is not running, but also once the engine has been started, so as to control the management
of the vehicle motion, propulsion and additional braking.
[0007] An object of the present invention is a device for preventing unauthorized starting
of a vehicle, that comprises means for authenticating an ignition key, characterized
in that it comprises a control means that determines the activation of the propulsion
functions, and the control of the motion and of additional braking systems on the
basis of said authentication of the ignition key.
[0008] In particular this invention relates to a device and method for preventing unauthorized
starting of a vehicle, as better described in the claims, which are an integral part
of this description.
[0009] The purposes and advantages of this invention will become clear from the following
detailed description of a preferred embodiment and of its variants and from the drawings
that are attached hereto, which are merely illustrative and not limitative, in which:
figure 1 is a block diagram of the device according to this invention;
figure 2 is an operational flow chart of the method according to the present invention.
[0010] In fig.1 VCM indicates the immobilizer module according to the present invention.
[0011] The VCM consists of an electronic device that communicates with an ignition key KEY.
[0012] The procedure uses a conventional transponder link to identify and enable the key.
Each KEY is identified by means of a unique code that is stored in the VCM during
manufacturing, thus creating an univocal association between a given number of keys
and the VCM of a vehicle.
[0013] Whether or not the KEY is identified as valid determines whether a series of functions,
which are described below, are enabled or disabled.
[0014] The VCM controls the operation of a module ECM that manages the delivery of fuel
to the engine. The VCM enables operation of the ECM if the ignition KEY is identified
as valid.
[0015] The modules VCM and ECM dialogue via a conventional encrypted protocol according
to the SAE J1939/71 standard, using a "challenge/response" technique to exchange messages.
[0016] The VCM manages the functioning of the engine brake FM and of the module INT that
manages the vehicle's additional braking systems: the INT controls the electric braking
systems, such as the hydraulic or electromagnetic retarder.
[0017] The VCM manages requests to activate the engine brake FM and the module INT. If the
KEY is not identified as valid, the VCM blocks the additional braking systems in the
braking position so that the vehicle cannot move.
[0018] When the accelerator pedal ACC is operated, the VCM uses a torque map to control
the amount of engine torque requested, where torque = f (Engine Speed, Accelerator
Pedal Position), called the Driveability map. The request for torque is managed by
the VCM, which only allows torque to be transmitted if the key has been identified
as valid. The torque map is stored in the VCM.
[0019] The VCM manages requests for engine torque from the transmission system TRM (basically
the clutch, gearbox). If the KEY is not identified as valid, the VCM blocks the torque
control requests from the Transmission Control module to engage the gears and open/close
the clutch, thus preventing gear change. This control function is enabled in case
of an automatic transmission system.
[0020] The VCM enables the activation of the starting motor (cranking) CRK, which is blocked
if the KEY is not identified as valid.
[0021] The VCM controls an electronic control module BDY that manages the control functions
of the electric circuit, such as lights, electric windows, etc. If the key is not
identified as valid, the BDY activates the horn and/or hazard warning lights.
[0022] If the key is not identified as valid, the VCM enables the use of an emergency starting
procedure, which is also used in case of problems, for example if the key is lost
or broken.
[0023] In that case, a manual starting procedure is performed by entering an unblocking
PIN code from the instrument panel (keypad on the steering wheel). Only the driver
knows this code, which is previously stored in the VCM.
[0024] In this case, when the correct PIN code is entered the control module enables all
vehicle functions, in exactly the same way as when the KEY is identified as valid.
[0025] From the description set forth above it is apparent that the main characteristic
of the device (VCM) for preventing unauthorized starting of a vehicle, according to
this invention, consists of determining the activation of the vehicle's propulsion
functions and the management circuits of the power transmission and motion control
and additional braking systems on the basis of the authentication of the ignition
key (KEY).
[0026] The person skilled in the art will have no difficulty in embodying the module VCM
on the basis of the functions described above. The VCM comprises a series of shut-off
functions that are controlled on the basis of the authentication of the KEY.
[0027] Such functions may be embodied by means of a program, for example written in C language,
using a normal automotive software system.
[0028] As regards the illustration of the method of operation, reference is made to the
operational flow chart in figure 2, which is useful for describing the method of vehicle
immobilization according to the present invention.
[0029] In the first phase 1 the KEY authentication procedure is carried out.
[0030] If the key is authenticated (phase 2 - YES), the VCM authorizes all the systems controlled
thereby to become fully operational (phase 3), and thus:
- the starting motor CRK is unblocked;
- the fuel delivery system ECM is unblocked;
- the transmission system TRM is unblocked and fully operational;
- the management circuits of the engine brake FM and additional braking system INT are
unblocked;
- all functions in connection with the use of the accelerator pedal ACC to request torque
are unblocked;
- the hazard warning lights and the acoustic alarm of the electronic control module
BDY are not activated;
[0031] If the key is not authenticated (phase 2 - NO), the VCM enables the use of the emergency
starting procedure (phase 4 in which the PIN code can be entered to unblock the system
manually).
[0032] If the PIN code is not entered, or if the PIN code is incorrect after a maximum number
of attempts (phase 5 - NO), the VCM immobilizes the vehicle (phase 6), and thus:
- the starting motor CRK is blocked;
- the delivery of fuel to the engine ECM is blocked;
requests for torque from the transmission system TRM are blocked;
the request for torque from the accelerator pedal ACC is blocked;
the engine brake FM and additional braking system INT are activated;
- the hazard warning lights and acoustic alarm are activated.
[0033] Alternatively, if the PIN code is entered correctly (phase 5 - YES), the system acts
in exactly the same way as when the KEY is identified as valid, and goes to the phase
3 described above.
[0034] In the unlikely event of the vehicle's engine being started in a fraudulent manner,
even though the ignition KEY has not been authenticated, i.e. by bypassing the KEY
and PIN code validation procedures, the VCM is able to switch to a degraded operation
mode (phase 7) in which for example the VCM only allows the accelerator ACC to request
minimum engine torque, limiting the number of engine revolutions (e.g. maximum 1000
RPM), and/or may only authorize the transmission module TRM to enable engagement of
the 1
st gear, and/or may activate the vehicle's braking system.
[0035] This invention can be implemented advantageously in a computer program comprising
program code means for performing one or more steps of such method, when such program
is run on a computer. For this reason the patent shall also cover such computer program
and the computer-readable medium that comprises a recorded message, such computer-readable
medium comprising the program code means for performing one or more steps of such
method, when such program is run on a computer.
[0036] It will be apparent to the person skilled in the art that other alternative and equivalent
embodiments of the invention can be conceived and reduced to practice without departing
from the scope of the present invention.
[0037] It will be possible for the person skilled in the art to embody the invention without
introducing any further construction details.
1. Device for preventing unauthorized starting of a vehicle, comprising means for authenticating
an ignition key (KEY),
characterized in that it comprises:
a control module (VCM) that determines the activation of the vehicle's propulsion
functions, of the management of the motion and additional braking on the basis of
said authentication of the ignition key (KEY).
2. Device according to claim 1,
characterized in that said control module (VCM) comprises:
- means for activating the delivery of fuel (ECM) to the engine;
- means for activating the vehicle's additional braking functions (FM, INT);
- means for activating a map of the torque requested by the vehicle's accelerator
pedal (ACC) ;
- means for managing the amount of engine torque requested by the vehicle's transmission
systems (TRM);
- means for activating the vehicle's starting motor (CRK);
- means for activating the vehicle's acoustic alarms and/or hazard lights (BDY).
3. Device according to claim 1 or 2, characterized in that said control module (VCM) also comprises means for enabling an emergency starting
procedure (PIN) that, if said ignition key (KEY) authentication fails, activates a
procedure for entering an unblocking code and that, if said unblocking code is entered
correctly, determines the activation of said propulsion functions, of the management
of the motion and of additional braking systems or, if said unblocking code is entered
incorrectly, determines the complete immobilization of the vehicle.
4. Device according to claim 1 or 2,
characterized in that said control module (VCM) also comprises means for activating a degraded vehicle
operation mode that, if the engine is started in spite of the fact that the ignition
key (KEY) has not been authenticated:
- limits the maximum number of engine revolutions and/or;
- limits the gear ratios that can be engaged and/or;
- activates the vehicle's braking system.
5. Method for preventing unauthorized starting of a vehicle,
characterized in that it comprises the following steps:
- authentication of an ignition key (KEY);
- if the key is authenticated (phase 2 - YES), the system authorizes complete operation
of the propulsion functions, of the management of the motion and of the additional
braking systems (phase 3);
- if the key is not authenticated (phase 2 - NO), an emergency starting procedure
is activated (phase 4) in order to enter an unblocking code (PIN);
- if said unblocking code is entered correctly, the complete operation of the propulsion
functions, of the management of the motion control and of additional braking systems
is authorised (phase 3);
- if said unblocking code is not entered correctly, the vehicle is completely blocked
(phase 6).
6. Method according to claim 5,
characterized in that it comprises an additional step of degraded vehicle operation that, if the ignition
key (KEY) is not authenticated:
- limits the maximum number of engine revolutions and/or;
- limits the gear ratios that can be engaged and/or;
- activates the vehicle's braking system.
7. Computer program comprising program code means for performing the steps in claims
5 and 6, when said program is run on a computer.
8. Computer-readable medium comprising a recorded program, said computer-readable medium
comprising the program code means in order to perform the steps in claims 5 and 6,
when said program is run on a computer.